1. Field of the Invention
The present invention is a patio umbrella that includes a fuel-burning radiant heater and a dining table.
It frequently happens that outdoor temperature ranges from comfortably warm at mid-day to chilly in the evenings. The comfortable mid-day temperatures are an incentive for restaurant owners to provide facilities for outdoor patio dining. However, construction of such facilities is predicated on their efficient use, which is somewhat marginal unless steps are taken to insure the comfort of the customers throughout a substantial portion of the entire day, including the cooler hours.
To this end, outdoor patios are often provided with radiant heaters that burn natural gas or propane gas. Heaters of this type are available from a number of manufacturers. A typical heater of this type is approximately 93 inches tall. The combustion chamber is supported by a hollow column that extends upward from the floor, and a reflector in the shape of an inverted dish is located above the combustion chamber for the purpose of reflecting radiant heat downward that would otherwise travel skyward.
Ordinarily, when radiant heaters are installed on a patio, they are placed between the tables where they become an obstacle for the service employees and for the customers alike. To provide adequate space for passage around the heaters, the tables must be more widely spaced, thereby rendering the patio less efficient.
Because the outdoor daytime temperature may be quite warm and because the patio may be subjected to direct sunshine, it is desirable to protect the customers from the direct sunshine by providing a large umbrella, often called a beach umbrella or patio umbrella. Such umbrellas typically measure 6 to 8 feet across, and they are not generally practical where high wind speeds prevail.
The present invention is one solution to the many problems that must be considered in combining a radiant heater with a large umbrella. It does not appear that such a combination has successfully been made prior to the present invention.
2. The Prior Art
In U.S. Pat. No. 3,295,473 issued Jan. 3, 1967, Wentworth describes a table mounted on the vertical shaft of a large umbrella, but there is no heater. Likewise, in U.S. Pat. No. 3,624,732 issued Nov. 30, 1971, Bowden also shows a vertically-adjustable table mounted on the vertical shaft of a large umbrella. Again, no suggestion of supplying heat is given.
In U.S. Pat. No. 3,739,972 issued Jun. 19, 1973, Holland describes a hand-carried rain umbrella in which the ribs of the umbrella incorporate electric heating elements that are operated by batteries within the shaft of the umbrella. Because this umbrella does not use a heater in which combustion occurs, the problems inherent in this umbrella are different from those encountered in the present invention.
In U.S. Pat. No. 3,625,235 issued Dec. 7, 1971 to Gorgichuk, there is shown a spherical shelter in which a stove sits on the floor, and a stovepipe extends vertically upward and through a hole at the top of the structure. Likewise, in U.S. Pat. No. 4,844,108 issued Jul. 4, 1989, Rohrer shows a tent containing a stove. The stove is located near the floor, and the tent is supported by a hollow vertical central column that serves as a chimney for the stove. A similar arrangement is shown in U.S. Pat. No. 2,601,865 issued Jul. 1, 1952 to Campbell.
In the patents of Gorgichuk, of Rohrer, and of Campbell, the stove is located on the ground or floor, and the top part of the stovepipe, which is nearest the tent, is far enough from the stove that the temperature of the top of the stovepipe is no great concern.
The following four patents show designs for poultry brooders: U.S. Pat. No. 1,584,877 issued May 18, 1926 to McCorkle; U.S. Pat. No. 2,985,137 issued May 23, 1961 to Horne; U.S. Pat. No. 3,349,752 issued Oct. 31, 1967; and, U.S. Pat. No. 4,614,166 issued Sep. 30, 1986 to Maurice. These patents show the use of a metal hood to reflect radiant heat downward onto the chicks. These patents do not show a cloth umbrella that can be opened and closed at will, and they do not suggest how the structure of such an umbrella can be integrated into the structure of the poultry brooder. Chicks in a brooder appear to have little interest in coming into contact with the hot metal parts of the brooder; however, humans on a restaurant patio can be expected to handle various parts of the umbrella frame. This is a problem not faced by brooder designers.
As the present inventors set out to combine an outdoor radiant combustion heater with a patio type umbrella for use in a restaurant environment, they were immediately faced by a number of severe problems.
The most obvious problem confronting the inventors was how to prevent the cloth canopy of the umbrella from overheating and either scorching or burning. In the preferred embodiment, the canopy of the umbrella is composed of a heavy fire-resistant canvas-like cloth, which nonetheless is susceptible to heat damage if subjected to a sufficiently high temperature.
Equally serious however was the problem of preventing the metallic umbrella frame structure from overheating and burning the hands of curious patrons. Also, a way had to be found to prevent the umbrella from being closed while the burner is still in operation.
A severe mechanical problem arose from the fact that the combustion chamber of the heater needed to occupy the space normally occupied by the hub of the umbrella.
Still other problems involved the flow of air. It was desired to retain the vent opening between the upper and lower canopies, which enables the umbrella to withstand stronger winds. Also, it was not apparent how to provide a supply of fresh air to the burner and to dispose of the hot products of combustion.
The present invention solves all of the aforementioned problems and the final product is safe and reliable.